Gastrointestinal (“GI”) bleeding is often associated with peptic ulcer disease (PUD) and can be fatal if not treated immediately. Hemorrhaging is the most dangerous procedure with which a Gastro-Intestinal Endoscopist has to deal. It is his/her only unplanned, emergency procedure where time is critical in determining the outcome. It is also the one problem the Endoscopist faces that is generally not an outpatient procedure. A bleeding PUD can be a critical clinical event as there is internal hemorrhaging. Ulcers are classified from clean to active spurting bleeding. The most worrisome are active bleeders and visible vessels. Untreated visible vessels are likely to bleed.
Suspected bleeding PUD patients can be diagnosed and treated endoscopically in an emergency room, an ICU or the GI suite. Surgery generally results in higher cost, morbidity and mortality than endoscopy. Therefore, laparoscopy or open surgery is not preferred unless there is no endoscopic alternative or endoscopy has failed. If the diseased tissue is beyond repair, a surgical gastric resection may be performed.
Currently, the endoscopist has two commonly used treatments and some lesser used therapies to achieve hemostasis of the ulcer. The most widely used treatments are thermal therapy and injection therapy. Some of the less common options are Olympus Endoclips, lasers and argon plasma cautery.
With thermal therapy, a catheter with a rigid heating element tip is passed through the working channel of an endoscope after the bleed is visualized and diagnosed. After the rigid catheter tip has exited the scope, the scope is manipulated to press the tip against the bleed site. Thermal power is applied, either through a resistive element in the tip or by applying RF energy through the tissue, thus desiccating and cauterizing the tissue. The combination of the tip compressing the tissue/vessel and the application of heat theoretically welds the vessel closed.
Although thermal treatment is fairly successful in achieving hemostasis, it often takes more than one attempt (irrigation is applied after the initial treatment to see if hemostasis has occurred) and there is frequent re-bleeding. Generally several pulses of energy are applied during each attempt. If early re-treatment is needed, there is a risk of perforation with the heat probe. Another disadvantage is that both types of thermal therapy require a specialized power generator and the equipment can be expensive.
With injection therapy, a catheter with a distally extendable hypo needle is passed through the working channel of the endoscope after the bleeding has been visualized and diagnosed. Once the catheter tip has exited the scope, the scope is manipulated to the bleed site, the needle is extended remotely and inserted into the bleed site. A vasoconstricting (narrowing of blood vessels) or sclerosing (causing a hardening of tissue) drug is then injected through the needle. Multiple injections in and around the bleeding site are often needed, until hemostasis has been′ achieved. As with thermal therapy, re-bleeding is also a problem.
The treatment used in any specific instance is highly dependent on geographic region. In some regions, especially in the United States, injection therapy is often combined with thermal treatment since neither therapy is completely effective alone.
The primary success rate of endoscopic treatment is about 90%. The other cases are usually referred to surgery. All identified ulcers may re-bleed at a later time, but the re-bleed rate for endoscopically treated active bleeds and a visible vessel is 10-30%. Even with the introduction of new treatments and devices, these rates have not improved significantly in decades. Surgery's short and long-term success for permanent hemostasis is virtually 100%.
Surgery has a higher success rate because the bleeding site is compressed mechanically, causing better hemostasis. Using devices such as clamps, clips, staples, sutures (i.e. devices able to apply sufficient constrictive forces to blood vessels so as to limit or interrupt blood flow), the bleeding vessel is ligated or the tissue around the bleed site is compressed, ligating all of the surrounding vessels.
An existing device that incorporates the advantages of surgery into a less-invasive endoscopic procedure is the Olympus EndoClip. The goal of the device is to pinch the bleeding vessel to create hemostasis. The problem with this device is that once jaw closure begins, it is not possible to reopen them, and the endoscopist is committed to firing the clip. In other words, jaw closure is not reversible. Because the vessel is frequently difficult to see, often several clips must be deployed in order to successfully pinch the vessel and achieve hemostasis. Additionally, the Olympus EndoClip is a semi-reusable device, causing the performance of the device to degrade with use.